Cache-Status Header: Debug CDN Hits and Misses (RFC 9211)
Learn how RFC 9211's Cache-Status header exposes hits, misses, forwards, and coalesced requests across your CDN chain. Includes vendor mapping and TTFB attribution patterns.
TTFB Articles
Server-Timing Header for TTFB Attribution: A 2026 RUM Guide
Break down Time to First Byte into named backend phases with the Server-Timing header. Includes syntax, CORS gotchas, Node/Workers/nginx examples, and RUM integration.
Stale-While-Revalidate Cache-Control: Hide Origin Latency Without Serving Bad Data
How to use the stale-while-revalidate Cache-Control directive to serve cached responses instantly while revalidating in the background. RFC 5861 recipes, CDN support in 2026, and footguns to avoid.
HTTP 103 Early Hints: Cut TTFB and LCP by Preloading During Server Think-Time
HTTP 103 Early Hints lets servers preload critical resources during backend think-time, cutting LCP by 100-400ms. A practical 2026 guide for Cloudflare, Fastly, and Node.js origins.
HTTP/3 and QUIC for Web Performance: A Practical 2026 Guide
HTTP/3 over QUIC removes TCP head-of-line blocking and cuts mobile load times 20-60%. Practical setup for Nginx, Caddy, and Cloudflare with a rollout plan.